J. Cosmet. Sci., 68, 114–125 ( January/February 2017) 114 Structure/property comparisons of chemistries based on renewable 1,3-propanediol and petroleum-derived alkylene oxides ERIC LIND, JOHN CHASE, PAT MAYER, JED RIEMER, MICHAEL ANTHONAVAGE, CAREN DRES-HAJESKI, and TOM RUSSO, Vantage Specialty Ingredients, Inc., Global Headquarters, Warren, NJ 07059 ( J.C., P.T., J.R., M.A., C.D., T.R.) and Vantage Performance Materials, Gurnee, IL 60031 (E.L.). Summary Structure/property comparisons were made of chemistries based on renewable 1,3-propanediol (PDO)- versus petroleum-based alkylene oxides as well as comparisons of the respective polyethers, emulsifi ers, and cosmetic formulations based on these feedstocks. Green Chemistry Principles were applied in the manufacture of polyethylene glycol (PEG)-free renewable PDO-based oligomers and PDO-based fatty acid ester emulsifi ers. Sustainable cosmetic products formulated with renewable PDO-based emulsifi ers gave equivalent performance in sensory and moisturization evaluations compared to those formulated with the petroleum-derived PEG- based emulsifi ers. INTRODUCTION Petroleum-based alkylene oxides, i.e., ethylene oxide (EO) (1) and propylene oxide (PO) monomers are widely used feedstocks for the production of polyethylene glycol (PEG) and polypropylene glycol (PPG) polyethers that fi nd application in a variety of industries. PEG and PPG are useful raw materials for the production of alkoxylated fatty acid and alkoxylated fatty alcohol surfactants/emulsifi ers used in the personal care industry. Some of the drawbacks of the ethoxylated nonionic surfactants include that they are petroleum based and contain residual levels of hazardous unreacted EO monomers and 1,4-dioxane by-products (2). For these reasons, there have been efforts to develop PEG-free alternatives. Examples of some of the commercially available PEG-free fatty acid esters include the polyglycerol esters, sorbitol esters, and sucrose esters (3–5). The later surfactants have found success as nonionic PEG-free alternatives in the personal care markets, although the ethoxylate-based chemistry still holds a large share of the nonionic surfactant market in personal care. There remains a need for more sustainable PEG-free nonionic surfactant Address all correspondence to Eric Lind at Eric.Lind@vantagegrp.com.

RENEWABLE PDO AND PETROLEUM-DERIVED ALKYLENE OXIDES 115 options that perform as well as the alkylene oxide–based nonionic surfactants in cosmetic applications. In this presentation, structure/property comparisons were made of chemis- tries based on renewable 1,3-propanediol (PDO)- and alkylene oxide–based feedstocks as well as the respective polyethers, emulsifi ers, and cosmetic formulations based on these feedstocks. Green Chemistry Principles were applied in the manufacture of sustainable PEG-free emulsifi ers that were evaluated in cosmetic applications. BIO-BASED PDO VERSUS PETROLEUM-DERIVED PEG-BASED CHEMISTRIES, STRUCTURE/PROPERTY COMPARISONS Bio-based PDO monomer is produced from the fermentation of renewable vegetable sources in accordance with the 12 principles of Green Chemistry (6). A life cycle assessment comparison found that from cradle to gate, the production of bio-PDO consumes 40% less energy and reduces greenhouse gas emissions by more than 40% versus petroleum- based PDO or propylene glycol (7). The structure/property differences of the feed- stocks used to produce the bio-based PDO monomer versus the EO and PO monomers have an impact on their safe handling and manufacturing processes (Figure 1). The PDO diol chemical structure has a greater degree of hydrogen bonding than the EO or PO and as a result has a higher boiling point (418°F)/low volatility. The bio-based PDO is made by the process of fermentation of sustainable plant-derived sugars at ambient tempera- tures and pressures. In contrast, the low boiling point/volatile (EO) (51°F) and PO are made under high pressures (150 psi or more) from their low-boiling ethylene and propyl- ene petroleum-derived feedstocks, respectively. The resulting EO and PO monomers are highly reactive due to the three-membered epoxy ring structures with strained carbon– oxygen–carbon bond angles of ~60° versus the less strained PDO carbon–oxygen–hydrogen bond angles of ~110°. Engineering safety controls, including EO and PO sensors, are necessary to ensure that accidental releases of the highly fl ammable, toxic, and potentially explosive EO and PO are detected early and resolved. Acid-catalyzed condensation of the bio-based PDO monomer produced poly-PDO (PPDO) polyether oligomers (8,9) (Figure 1). Figure 1. Feedstocks used to produce bio-based and petroleum-based products.